Forty power microscope objective

ABSTRACT

A three component microscope objective having a -numerical aperture of substantially 0.66 and a magnification -of substantially 40X is provided by a three element system. -The microscope objective provides correction for the usual -chromatic image aberrations as well as spherical aberration, -coma, and astigmatism while having a substantially flat image -field.

United State Shoemaker FORTY POWER MICROSCOPE OBJECTIVE [75] lnventor:Arthur H. Shoemaker, East Aurora, N.Y.

[73} Assignee: American Optical Corporation,

Southbridge, Mass.

221 Filed: July 9, 1973 m App]. Na; 377,870

[52] US. Cl 350/225, 350/175 ML, 350/229 [5 I] Int. Cl. G02b 9/12 [58]Field of Search 350/175 ML, 225, 229

[56] References Cited 7 UNITED STATES PATENTS 2,713,808 7/1955 Klein350/175 ML [451 Feb. 25, 1975 Shoemaker 350/225 X Primary Examiner-PaulA. Sacher Attorney, Agent, or Firm-Alan H.'Spencer; William C. Nealon;H. R. Berkenstock, Jr.

[57] ABSTRACT 2 Claims, 1 Drawing Figure Shoemaker 350/225 X FORTY POWERMICROSCOPE OBJECTIVE THE INVENTION 2 lll designatethe three opticallyaligned components of said objective. The foremost component, componentI is a concavo-convex positive lens followed by components II and IIIwhich are both double convex positive doublets.

The lens parameters are as follows: The successive radii are designatedRl-R8, where a minus sign indicates radii on centers of curvature lyingon the object side of their vertices. The axial thicknesses of succeslsive lenses are designated Tl-TS. The refractive indices of the glassesin successive lens element are designated NDl-NDS and the Abbe Numbersof the successive glasses are designated vl-vS. The index of refractionand Abbe Numbers are absolute values.

Refractive Abbe Radius Thickness Space Index Number R r s ND u S,=.l566FR,= .6lS5F l T =.7637F ND =l.69669 v =56.l3

s.,=.0467F R 4.3553F II T =l3273F ND,=I.78446 v,=25.75

RF l.285()F T =.6546F ND -;=l 69669 "F5613 R l.79l4F S; =l.2l52I R9.214% Ill T =.3273F ND =l.7lil6l 0 :37.08

R l.3725F T,,=.b546F ND,,==|.5UI29 v;==56.39 R-= 3.]KIIF THE DRAWING Apreferred embodiment of the invention having a The drawing is an opticaldiagram. of a mlcroscope focatl lbelngth F equal to 4583 18 set forth inthe follow objective according to the present invention. mg

Refractive Abbe Radius Thickness Space Index Number R T 5 ND 1' s,= .718R,- 2.2m I T =3.500 ND l .6966) u =56. l 3

s .214 R; 19960 T.,=i.500 ND =L78446 v.,=25.75

TFILOOO ND -l.69669 vf56.l3 R 8.210 1- r s,=5.569 R 42.23] III T =l.5O0ND -1.78l6l v =37.08

T ,,=3 O()O ND =l.5Ol29 v,,=56.39 R,.= l5.5(]() FIG. I is an opticaldiagram of the preferred form of the present invention wherein thenumeral X designates the objective in general. and numerals I, II, and

It will be apparent that the foregoing is variable depending on thevalue of F. Other forms are thus possible and changes may be made in thevalues of the con- 3,868,175 3 4 structional data based on therelationships with the nesses (T), axial spaces along lens element andobject above charts, without departing from the spirit of this plane(S), refractive indices (ND), and Abbe Numbers invention. (1/), aredetermined by the following relationship:

Refractive Abbe Radius Thickness Space lndex Number R T ND v s,= .l566FR .6l55F ND =l.69669 v,=56.l3 l T,=.7637F s.,= .0467F R3= 4.3553F u T,=3273F ND.,=L78446 u- 1=25.75

R4= lr2850F T =i6546F ND,=1.69669 mg -5613 R,,= -l.79l4F S -l.2l5 F R9.2148F lll T,=.3273F ND =l.78l6l u,=37.o8

R7= lr3725F T;,=.6546F ND =l.50l29 v =5ot39 R,.= 3.382lF What is claimedis: wherein scalar values are given in millimeters.

l. A three component microscope ObjCCUVE compris- .2. The microscopeobjective of claim 1 wherein the ing a positive concave-convex lens asthe first compoparameters of radll (R), lens thickness (T), axial spacesnent (l). a double convex positive doublet (ll) as the along lenselement and ob ect plane (S), refractive insecond component and a doubleconvex positive doudices (ND), and Abbe Numbers (v), being determ nedblet (lll) as the third component having a magnificaby the followingrelationship Refractive Abbe Radius Thickness Space Index Number R T 5ND 1/ S,= .718 R 2.821 I T=3.5OO ND,=|.69669 v,=56.l3

S2= .214 R 19.960 11 T =l.500 ND-,=l.78446 v,=25.75

T ,=3,000 ND3=L69669 u =56.l3 R 8.210

S =5569 R 42 31 m T;=1.500 ND,=1.78161 v,=37.08

T,,=3.000 ND LSOlZQ v =56.39 RN= l5.500

. 45 tion of 40X and a numerical aperture of approximately whereinscalar values are given in millimeters. 0.66 wherein the parameters ofradii.(R), lens thick-

1. A three component microscope objective comprising a positiveconcavo-convex lens as the first component (I), a double convex positivedoublet (II) as the second component and a double convex positivedoublet (III) as the third component having a magnification of 40 X anda numerical aperture of approximately 0.66 wherein the parameters ofradii (R), lens thicknesses (T), axial spaces along lens element andobject plane (S), refractive indices (ND), and Abbe Numbers ( Nu ), aredetermined by the following relationship:
 2. The microscope objective ofclaim 1 wherein the parameters of radii (R), lens thickness (T), axialspaces along lens element and object plane (S), refractive indices (ND),and Abbe Numbers ( Nu ), being determined by the following relationship